SUBSTANCES PRODUCED BY FUNGI 205 



Tests are also made for sterility, moisture content, presence of pyro- 

 genic substances, and toxicity (248). 



By means of adsorption, distribution between solvents, and reduc- 

 tion, a barium salt or penicillin was at first obtained (5, 6) which was 

 homogeneous by chromatographic analysis and gave 450 to 500 Oxford 

 units per milligram of dry material. The active substance was found to 

 be a salt of a strong dibasic acid with fH values approximately 2.3 and 

 2.5. The molecule contained one carboxyl, one latent carboxylic, two 

 acetylatable, at least five C-Me groups, and no easily reducible double 

 bond. The penicillin thus prepared was more sensitive to oxidizing 

 agents than to reducing agents j it was unstable toward dilute acids and 

 alkalies, and to heat (loss of COo), primary alcohols, and various heavy 

 metal ions. Tentative suggestions were made concerning its chemical 

 nature as follows: (a) a polysubstituted hydroaromatic ring structure j 

 (b) the acidic groups (carboxyl) not conjugated with the chromophore 

 responsible for the absorption j (c) the possible presence of a trisubsti- 

 tuted a-unsaturated ketone grouping. 



With the introduction of new cultures for the production of penicil- 

 lin, with the development of new methods for the growth of the or- 

 ganism, as submerged vs. stationary, and especially with the employ- 

 ment of synthetic media, it was found that several forms of penicillin 

 are produced (735). 



P. chrysogenum x 1,612 was found to yield about 100 O.U./ml. The 

 penicillin molecule is readily synthesized, especially when a phenyl 

 linkage has been supplied. The addition of 3.3 gm./L of phenylacetic 

 acid to the medium gave a maximum yield of 244 O.U./ml. 



P. notatum 1,984-A yields 40 to 50 O.U./ml. of penicillin on a 

 purely synthetic medium, in presence of such factors as indole acetic 

 acid or naphthalene acetic acid. The production of penicillin takes place 

 in the presence of the following groups: 



I. Cysteine (or cystine in presence of a suitable reducing agent such 

 as sulfite waste liquor) 

 . 2. The — C — C — N — chain with the proper linkage at each end 



II I 



O H 



